JSch addIdentity - How to pass private and public key strings vs. file path

Question

There are a lot of examples on this, but none of them show a working example on how use the .ppk public/private file components in a string form converted to a byte[] and used with the JSch.addIdentity(String,byte[],byte[],byte[]) method. Can someone look at the following method and let me know where I'm going wrong. It doesn't like the strings converted to a byte[]. The strings are not in full for security reasons, but I think you'll get the point of what I'm trying accomplish with this. Unfortunately, I'm stuck using strings for this since I cannot use the .ppk file directly.

public void InitChannelSftp() throws JSchException {
    JSch ssh = new JSch();
    session_ = ssh.getSession(userName_, host_, port_);
    session_.setConfig("StrictHostKeyChecking", "no");
    
    String passPhrase= "trustNoOne";

    String privateKey= "-----BEGIN RSA PRIVATE KEY-----\n" +
            "hvbytegNktMU05bc3QlCrSs+YHkMAvZRkzcjaXDdcKDfSZyDqcFHfkup1N6CMDg4\n" +
            "yZh0ou+7G8jDQtn29YoAO0tpEW4EGQiI6918iMk22012ytcsCnM80/hj1JbVa4St\n" +
            "1StZKJtBYSu1bRZCpFPygditUGc9pZhDWfgDxLTzQdDMcmdvMb9AgpNKZAz8n0OR\n" +
            "2tuGPAogbt8e48ad9H7IYuikhIqQU42DkrAqRPJDUZqP3gGdzwstuDPl1dwrRaCs\n" +
            "vTynsEMDCjVjNyxRK9sbBO/BwFTaFRM2oN4BvCbfbQKyhRrXZ1gjNMv1P5GxchKj\n"+
            "-----END RSA PRIVATE KEY-----\n";

    String publicKey= "-----BEGIN SH2 PUBLIC KEY-----\n" +
            "AAAAB3NzaC1yc2EAAAABJQAAAQEA6wXxLoqF70gkd2hURVlmq+iPCBPmkZ6IwCST\n" +
            "nlxHY/Jc0izbn+6hyFUZmS53LN9CJyjjVvU+UAWapU2tTJKwO6aI8xcKmtBjdDeS\n" +
            "GJgh6C+srGFlbNTXzV8sMmGEQirLyTOMwGviRFOhKn5/bUbqpw==\n" +
            "-----BEGIN SH2 PUBLIC KEY-----\n"


    ssh.addIdentity(
        "Test Conn", privateKey.getBytes(StandardCharsets.US_ASCII),
        publicKey.getBytes(StandardCharsets.US_ASCII), passPhrase.getBytes());

    session_.connect();
    channel_ = session_.openChannel("sftp");
    channel_.connect();
    ChannelSftp sftp_ = (ChannelSftp) channel_;
}

Error:

com.jcraft.jsch.JSchException: invalid privatekey: [B@25be7b63

Answer 1

Charset charset = StandardCharsets.UTF_8;
ssh.addIdentity(
    UUID.randomUUID().toString(), privateKey.getBytes(charset),
    publicKey.getBytes(charset), passPhrase.getBytes(charset));

The following private key format works:

-----BEGIN RSA PRIVATE KEY-----
Proc-Type: 4,ENCRYPTED
DEK-Info: DES-EDE3-CBC,322A25B18A52EDD1

Pwb2h8N...x8ijUQ==
-----END RSA PRIVATE KEY-----

A blank line at the end is not needed.

In PuTTY, this is achieved via Conversions > Export OpenSSH key.